Gravity readings tell us what’s inside Ceres

Gravity readings tell us what’s inside Ceres

As a bench scientist, normally when I say “data will be forthcoming,” there’s a certain delay implied. Data will be forthcoming after a certain delta-t. But NASA apparently has different ideas. Well after its planned EOL, the Dawn orbiter was still in good health, so at the end of July, NASA extended its mission at the dwarf planet Ceres. Without missing a beat, Dawn just batched us a ton of data about Ceres’ interior structure.

In addition to a slew of photos, Dawn also provides information about gravity fields it moves through, by way of NASA’s Deep Space Network. The DSN monitors the Doppler shift from the spacecraft, and it can pick up variations in speed as small as 0.1mm/sec. This extreme precision lets it use the gravitational inconsistencies of Ceres’ interior to tell us about what the planet must be made of inside.


Ceres’ unusual bright spots demonstrated there could be more to the planetoid than met the eye

It appears that, during a heating phase early in the history of Ceres, water and other light materials partially separated from rock and floated up to the outer layer of Ceres. This process is called “differentiation,” and it’s exactly like how our own planet’s core separated from the mantle and crust. But Ceres’ layers aren’t so distinct. The messy divisions between rock, ice, and gravely debris suggest that the interior structure of the iceball dwarf planet is changed by its rotation, since it doesn’t experience much tidal force.

Tiny perturbations in the gravitational environment around Ceres can tell us about how its slushy innards move around. Dawn can pick up these perturbations, using its participation with NASA’s DSN. Anomalies in the field around Ceres are how we know that its interior is both layered and relatively messy.

Scientists also discovered that higher-elevation areas on Ceres displace mass in the interior, much like how a boat floats on water: The volume of water displaced depends on the mass of the boat. They conclude that Ceres’ soft, icy mantle can be pushed aside by the ponderous mass of mountains, as if the high-elevation areas were floating on the material below.

The icy upper layer also supports the idea that Ceres’ strangely crater-free surface might be a result of its own structural properties. Frost heave could have obliterated the biggest craters on Ceres, and if most of the surface is ice, there’s a lot of frost to heave. Further readings will help to confirm or correct this hypothesis, and despite Dawn’s dwindling fuel reserves, it will be in orbit collecting data until at least 2019.

A lot of NASA’s equipment seems to be pretty busted and janky these days — Curiosity keeps going into safety mode, Dawn’s running out of fuel, Kepler’s reaction wheels are jammed, and Hubble is straight-up on its last legs. But they’re making it a point to do what they can with what they have — how can they do otherwise? Dawn still has a fair bit of its hydrazine as well as the use of its ion engine, which is why NASA extended the mission. Make hay while the sun shines.

Source: ExtremeTech

This week in space: Ceres, Io, and an interesting answer to the Fermi paradox

This week in space: Ceres, Io, and an interesting answer to the Fermi paradox

From exoplanet research and Io’s unusual atmosphere to triple supernovas, it’s been an interesting week. Here’s what you may have missed in space and space technology.

Superbubbles in space

Astronomers found a rare triple “superbubble” in a star nursery in M33, our nearest galactic neighbor. Three concentric supernovae form a glowing triple shell around a cluster of young stars. Scientists are examining this large-scale structure and other such odd birds to learn more about how galaxies, and the universe as a whole, evolved.

A new angle on the Fermi paradox

From Harvard this week comes a compelling and evidence-based answer to the evergreen question: if there’s life beyond our planet, where is it?

The scientists’ logic goes like this: Our sun is an unexceptional G-type main-sequence yellow dwarf. It’s about 4.5 billion years old, more or less typical for a star of its mass. Above three solar masses or so, stars don’t live too long — they expire violently, which the Harvard team thinks means the biggest stars die before complex life could have a chance to evolve. On the other end of the scale, on planets whose atmosphere survived the dangerous early lives of extremely long-lived red dwarf stars, life could take off at its leisure. In such a star system, the probability of life grows by orders of magnitude into the distant future.

In the current generation of stars, we’re probably coming along relatively early in the grand scheme of things. Like the kid with the September birthday, we’re among the first born in our class; the report concludes that in terms of star lifetimes, which is to say in terms of time to emergence of life, we and our Sun are precocious, probably within the first percentile. Those familiar with the Great Filter theory, though, may note that this means that the Great Filter is yet before us.

Arguments that are founded in “but we’re special” logic are difficult to support, but wouldn’t it be something if we turned out to be one of the First Ones? We humans, with all our stories about the Old Ones, the Outsiders, those from Beyond the Rim — wouldn’t it be funny if the Old Ones turned out to be us?

Gravity readings let us look inside Ceres

Ceres is the biggest thing in the asteroid belt between Mars and Jupiter. As a dwarf planet with an ice-ball surface covered in frozen ammonia, it’s solidly unattractive for human habitation or even mining. But we’ve got a satellite around it taking spectrographic and gravity readings so we can answer questions about the formation of our own rocky little planet. Recent data from Dawn tells us that Ceres’ interior is made of layers of rock, gravel, and ice, but the boundaries between its layers are messy.

Bright, bluish places represent salty, sulfurous ice. Image: NASA

Occator Crater, the brightest place on Ceres. Blue represents salty, sulfate-rich ice. Image: NASA

We think Ceres’ internal structure is mostly dictated by its movement, because it doesn’t experience much in the way of tidal forces, and it also doesn’t seem to have changed much since the initial heating event during which the planet’s structure differentiated. Having an outer layer composed mainly of ice supports the theory that emergent properties of Ceres’ own structure are responsible for its strangely crater-less surface.

Io and its amazing bouncing atmosphere

It’s hard to be superlative about this. Once a day, every day, Io’s sulfur dioxide atmosphere freezes and falls to the surface while Jupiter eclipses the sun. Once the sun strikes the surface again, the SO2 frost sublimates into a gas, and the little moon’s delicate atmosphere bounces right back.

Thanks to recent readings from Juno, too, our portrait of Jupiter and its moons keeps getting better. Io is a frigid, sulfurous moonsicle racked by cryovolcanic eruptions and bombarded by radiation. On second thought, let’s not go to Io. ‘Tis a silly place.

Image: SWRI

Io’s surface. Yikes. Image: SWRI

Gorgeous light show, no telescope necessary

Also, this is actually a preview for next week, but: If you want to watch a meteor shower that won’t disappoint, check out the Perseids. They will peak in intensity over the nights between August 11-12 and 12-13, sometimes approaching rates of 200 meteors per hour — about double their usual count.

Why so intense? As the Earth passes into the orbital path of the Swift-Tuttle comet, its debris form the Perseid shower. But this year, there’s a happy confluence of circumstance. Jupiter’s position in its own orbit means that it’s nudging a greater share of comet debris into our path than we see in most years.

While the Perseids aren’t yet at their peak, they’ve already started, so watch the live webcast from NASA. Better yet, go outside and look up!

Source: ExtremeTech

NASA’s TESS mission on track to start hunting exoplanets in 2017

NASA’s TESS mission on track to start hunting exoplanets in 2017

Ever since it debuted in 2009, NASA’s Kepler spacecraft has redefined our understanding of other star systems. But Kepler is in rough shape, and it won’t last forever. Now TESS, the Transiting Exoplanet Survey Satellite, is ticking along on schedule to launch in 2017. While the upcoming James Webb Space Telescope (JWST) is set to be a partial replacement for the Hubble telescope, the JWST will also be a sort of spiritual successor to Kepler, in that it will team up with TESS to hunt for exoplanets in the visible and IR bands.

Like Kepler, TESS will use the transit method, searching for exoplanets by watching hundreds of thousands of stars for the telltale dimming. But where Kepler must cast its eyes to a small patch of distant space, peering deeply but narrowly into the skies, TESS will make a shallower whole-sky survey of stars within a few hundred light years of Earth. Most of Kepler’s exoplanet discoveries came from one relatively small patch of the sky. But NASA officials say that TESS should be able to look at over 200,000 stars.

To make things easier for mission scientists, TESS breaks up its spherical viewfield into 26 “tiles” that overlap near its north and south poles. “The spacecraft’s powerful cameras will look continuously at each tile for just over 27 days, measuring visible light from the brightest targets every 2 minutes,” NASA officials said in a statement. Based on the characteristics of those little dips in brightness, TESS scientists will be able to tell how big the newly discovered exoplanets are, and how long they take to orbit their parent stars.

Left: The combined field of view of the four TESS cameras. Middle: Division of the celestial sphere into 26 observation sectors (13 per hemisphere). Right: Duration of observations on the celestial sphere. The dashed black circle enclosing the ecliptic pole shows the region which JWST will be able to observe at any time. Image and caption via GSFC/NASA

Now, TESS is an Explorer-class spacecraft, so it isn’t like Hubble or the other Great Observatories. A better comparison might be the Explorer-class Swift spacecraft, which is watching for gamma ray bursts. If it seems like two minutes isn’t very long to look at a star, it isn’t; TESS will take relatively brief glances, because it’s looking at a greater total area of the sky. But since the camera’s viewfields overlap at the poles, some places will be under almost constant observation. The idea is to follow up on TESS’s discoveries of potentially habitable worlds using the Observatory-class JWST, slated to launch in 2018 for really real this time.

Image via GSFC/NASA

That’s not all TESS has up its sleeve, though. While it will be a planet hunter first and foremost, scientists and other “guest investigators” will also have the opportunity to take time on TESS to observe black holes, supernovas, and a variety of other cosmic objects and phenomena.

One of the other major goals of TESS is to examine short-period objects and transient phenomena, like the visible light energy that accompanies a gamma ray burst. The spacecraft’s glancing gaze might pose difficulties for asteroseismologists, because while transits might take some days or weeks, starquakes can happen in seconds, so TESS’s sampling rate might bump into the Nyquist limit. But that kind of data loss is apparently a niche enough problem that project scientists were willing to make the compromise.

TESS also has unique orbital characteristics. It’s designed to survey both the northern and southern hemispheres and will use a new lunar orbit, dubbed P/2, to do so. This highly elliptical orbit will allow the spacecraft to survey its target range while simultaneously remaining balanced between the gravitational effects of the Moon and those of the Earth. NASA has published an article with more details on the spacecraft’s orbit and its characteristics, if you’re curious.

TESS's never-before-used P/2 orbit. Image: GSFC/NASA

TESS’s never-before-used P/2 orbit. Image: GSFC/NASA

Between TESS and the JWST, our understanding of other solar systems should continue to advance for years to come, even as monuments like Hubble and Kepler are taken offline. The toolkit of astronomers continues to expand as technology gets thinner, lighter, stronger, and more durable. When TESS makes it to space aboard a Falcon 9 FT rocket, it will fill a gap in data collection and, no doubt, present new problems to be overcome. But if we can beat gimbal lock, jammed reaction wheels, and broken rover arms while still making do under an endless funding drought, believe it, we’ll get some good science out of TESS.

Source: ExtremeTech

Science fiction becomes science fact with a better look at Jupiter’s moon Io

Science fiction becomes science fact with a better look at Jupiter’s moon Io

Remember that old sci-fi story, “A Pail of Air” by Fritz Leiber, where the Earth got stolen away from Sol by a dead star whizzing through, and everything froze solid and the Earth’s whole atmosphere snowed out of the sky? New research from the Southwest Research Institute shows that exactly that process is happening on Io, except on a daily basis.

Well, not the stolen-by-a-rogue-star part. None of that yet. But for two hours out of every day on Io, when Jupiter eclipses the Sun and its warmth, the moon’s surface temperature plummets from the positively summery -235F to a frigid -270F. The influx of solar energy stops. And Io’s atmosphere of sulfur dioxide falters, contracts, and then snows right out of its sky. When the solar eclipse ends, sublimation of all that SO2 snow pumps up the atmosphere again. It’s a “constant cycle of collapse and repair.”

Jupiter IO Artistic Concept FINAL

Io may be the real-world equivalent of Dante Alighieri’s nethermost circle of Hell. Its surface is a brutally cold, dry place, covered in yellow sulfur and rimed with crystalline sulfur dioxide frost. Racked with constant eruptions, Io is the most volcanically active place in our entire solar system. Tidal heating drives the volcanism: There’s so much orbital momentum being flung around as Io orbits Jupiter that the tidal forces keep the moon’s interior hot, even as the monumental tidal swell cracks the crust and lets basalt lava spout hundreds of miles into the sky. And the high-energy radiation belt in Io’s path means that every day the moon is bombarded with about 36 Sv equivalent. For reference, the lifetime acceptable dose for a human is well under 1 Sv.

Every aspect of this moon is punishing in the extreme, but nobody knew its atmosphere worked quite like this. Before this study, we hadn’t actually even managed to make any direct observations of Io’s atmosphere while it was in eclipse. What made it possible now was the combination of the huge Gemini North telescope and the TEXES system, which can see the atmosphere using thermal imaging when visible-spectrum instruments were blinded by Jupiter’s glare. “Though Io’s hyperactive volcanoes are the ultimate source of the SO2, sunlight controls the atmospheric pressure,” said John Spencer, coauthor. “We’ve long suspected this, but can finally watch it happen.”

Now that Juno has arrived in orbit, there should be a steady stream of data forthcoming on Jupiter and its moons. Instrumentation on Juno makes it possible to get much clearer readings on the gravitational fields, electromagnetic activity, and physical environs around Jupiter, so we’ll know more in the near future. In the meantime, go read some good sci-fi!

Source: ExtremeTech

This is your brain on physics: Scientists figure out how humans learn abstract concepts

This is your brain on physics: Scientists figure out how humans learn abstract concepts

How is it that we can use our brains, which evolved over hundreds of millennia, to manipulate abstract concepts like gravity, refraction, and inertia that we’ve only defined in the last few hundred years? It turns out that we use structures we developed long ago, networks we already use to process much more basic things like rhythm and language. Scientists from CMU report that the brain handles scientific abstractions “using inherent, re-purposed brain systems,” according to Robert Mason, coauthor of their latest study.

The researchers recruited nine advanced students of physics and engineering, put them into an fMRI at CMU’s Scientific Imaging and Brain Research (SIBR) Center, and asked them to contemplate high-level concepts like diffraction, displacement, radio waves, and centripetal force. Then they fed those brain scans into a machine learning model, and found that the brain lit up in certain places in response to certain physics concepts, regardless of which person was doing the contemplating.

Image: Mason, Just et al

Image: Mason, Just et al

Then they asked the model to identify what concept each of the students was thinking about, based only on those scans. It answered correctly, with ease. When trained on data from the other participants, it even knew exactly what an excluded participant was thinking of.

The model also figured out that under the hood, the brain is able to learn physics because it can understand the four fundamental concepts of “causal motion, periodicity, energy flow, and algebraic (sentence-like) representations.” We handle abstract concepts by adding complexity to neural firing patterns and “repurposing” the same structures we use to handle basic, intuitive concepts. Changing the software is cheap and easy compared with swapping out new hardware, here.

Brain systems that process rhythmic periodicity when hearing a horse gallop also support the understanding of wave concepts in physics. Similarly, understanding energy flow uses the same system as sensing warmth from a fire or the sun. Grasping how one concept relates to others in an equation uses the same brain systems that are used to comprehend sentences describing quantities.

Breakthroughs like this could change how we teach physics. Knowing what the brain is doing when it’s learning physics concepts is a powerful tool. It lets instructors tailor their curricula to what they’re trying to accomplish.

“If science teachers know how the brain is going to encode a new science concept, then they can define and elaborate that concept in ways that match the encoding,” said Mason. “They can teach to the brain by using the brain’s language.”

Source: ExtremeTech

Astronomers discover Russian nesting supernovas right next door

Astronomers discover Russian nesting supernovas right next door

Messier 33 is the third largest galaxy in our Local Group, with an estimated mass of 10 billion to 40 billion times the mass of our sun. Also known as the Triangulum galaxy for its location in the sky, M33 is home to some of the largest known star nurseries; its largest, NGC 604, is something like 100 times larger than the Orion Nebula. If it was as close to us as the Orion Nebula, it would be the brightest object in the night sky, save for the moon.

Because it’s so close, M33 is a perennial favorite of amateur astronomers. Italian astronomer Giovanni Battista Hodierna discovered it some time earlier than 1654, describing it as a nebula, before we even had a word for galaxies. But a team of astronomers using the 4.2m, optical-IR Herschel telescope have just turned up something truly remarkable in one of M33’s star nurseries: a cluster of new stars enclosed by a rare triple “superbubble,” concentric supernovae whose shells enclose each other like Russian nesting dolls in space.

All three shells formed the same way from individual stars: The first star went supernova and ejected a cloudy shell of matter into space, which slowed down and cooled as it went. Then the second supernova happened, with its shell of ejecta, and then the third. The outermost bubble is the slowest, coolest, and oldest of the trio at about 20,000 years old; the innermost ring formed maybe 5,000 years ago. And the clouds of gaseous ejecta are no trivial wisps. Each of these shells, the scientists estimate, is “a couple hundred times the mass of the Sun.”

NGC 604

Residing in M33, this is NGC 604, the star nursery NASA describes as “monstrous”. Image: NASA and The Hubble Heritage Team (AURA/STScI)

The hard science behind the discovery is pretty friendly. H-alpha (Hα) spectroscopy measures things like redshift and radial velocity. Using that information, the scientists can tell things like how long the shells have been traveling, and in what direction. “We can roughly calculate when the supernova explosions went off,” said John Beckman, coauthor. “We know how fast the shells are going and how big they are, so we can work out the shells’ ages.”

This discovery was part of a project called BUBBLY, which was established to find cosmic bubbles like these, floating in interstellar space. They vary in size from a few light years to a few thousand light years across. No fewer than 11 concentric superbubbles surround the Cat’s Eye nebula, for example, whose dying red giant core shed the mass equivalent of all the planets in our solar system every 1,500 years. Our own sun will spend some time as a red giant near its end of life.

Cat's Eye nebula

Cat’s Eye Nebula. Image: NASA, ESA, HEIC, and The Hubble Heritage Team (STScI/AURA)

Astronomers are collecting observations of these superbubbles in order to better understand the birth and death of stars, and the texture of interstellar space. As it turns out, interstellar space is lumpy; we know this because as these concentric but patchy superbubbles sweep outward, they pick up some gas from their surroundings. But only some. There’s some left for the next bubble, and some of it gets swept along with the shockwave, just like the first time.

Ultimately, superbubbles can teach us how the early universe evolved by telling us about how the first galaxies became enriched with metals. By peering across the eons into M33, we’re able to glimpse a process that was vital to life on Earth.

Source: ExtremeTech

This week in space: NASA fact-checks the Enterprise, Curiosity controls its own laser, and Ceres’ mysterious remodeling

This week in space: NASA fact-checks the Enterprise, Curiosity controls its own laser, and Ceres’ mysterious remodeling

Welcome to ExtremeTech’s weekly space-news round-up, where we cover the various goings-on of the solar system and worlds beyond. Here’s what happened this week, in case you missed it the first time around.

Curiosity is charging its laser

A remote update gave the Curiosity rover’s AI control over which rocks to vaporize with its on-board laser. In AEGIS mode, Curiosity’s ChemCam can choose between different kinds of Martian rock based on size, brightness, or surface features. Most ChemCam targets are still chosen by scientists on Earth, but the autonomous targeting adds a new capability. “This autonomy is particularly useful at times when getting the science team in the loop is difficult or impossible — in the middle of a long drive, perhaps, or when the schedules of Earth, Mars and spacecraft activities lead to delays in sharing information between the planets,” said robotics engineer Tara Estlin, leader of AEGIS development at JPL.

All Summer In A Day

Image: ESA

Using observations from the ESA’s Venus Express satellite, scientists showed for the first time how the topography of Venus’ surface informs its weather patterns.

“When winds push their way slowly across the mountainous slopes on the surface they generate something known as gravity waves,” explains Jean-Loup Bertaux of LATMOS, lead author of the report. “Despite the name, these have nothing to do with gravitational waves, which are ripples in space-time – instead, gravity waves are an atmospheric phenomenon we often see in mountainous parts of Earth’s surface.” Bertaux said they form when air ripples over bumpy surfaces, and that the waves then propagate vertically upwards, growing larger and larger in amplitude until they break just below the cloud-top, “like sea waves on a shoreline.”

“This certainly challenges our current General Circulation Models,” adds Håkan Svedhem, coauthor of the study and ESA Project Scientist for Venus Express. “While our models do acknowledge a connection between topography and climate, they don’t usually produce persistent weather patterns connected to topographical surface features. This is the first time that this connection has been shown clearly on Venus – it’s a major result.”

Earth, from a million miles away

Watch Earth spin through a full year in this time-lapse video, composed from thousands of snapshots taken by the DSCOVR satellite, which monitors our climate and solar wind from the Sun-Earth L1 point.

NASA’s Dawn mission extended

Dawn is still in solid shape at the end of its planned mission. Thanks to thrifty use of its hydrazine propellant, the orbiter can hold out against Ceres’ gravity for a while longer than we thought. To wring every last bit of data out of the orbiter, NASA extended the Dawn mission into 2019.

The top feature illustration for this post, by the way, is a shot of the Occator Crater on Ceres, a dwarf planet that lives in the asteroid belt between Mars and Jupiter. Blue areas represent salty places. Occator is the brightest spot on Ceres, but it’s a smallish crater, some 57 miles across; Ceres is unusually devoid of large impact craters. Astronomers suspect it’s the dwarf planet’s own makeup that reshapes its surface and removes all the big ones. “We concluded that a significant population of large craters on Ceres has been obliterated beyond recognition over geological time scales, which is likely the result of Ceres’ peculiar composition and internal evolution,” said lead investigator Simone Marchi of the SWRI.

Watch NASA engineers fact-check the starship Enterprise

Brian Muirhead, chief engineer at NASA’s JPL, and aerospace engineer Anita Sengupta poke at the plausibility of the starship Enterprise in this video by Wired. As it turns out, NASA has a lot to say about the science of Star Trek. We have magnetic shielding and we’re creeping up on VR, but that’s about as close as we can get to the technology of the Enterprise today. Happily, we have a couple hundred years to catch up.

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Source: ExtremeTech

Portable bioreactor from MIT produces medications, vaccines on-demand

Portable bioreactor from MIT produces medications, vaccines on-demand

Imagine a cross between one of those multi-color retractable pens and an epi-pen. But instead of colors, the device would have different medications. Now combine this with a tiny, droplet-sized sweatshop full of obedient single-celled organisms genetically engineered to produce those medications, and you’ve got what a team from MIT just published in Nature Communications: A new project, with funding from DARPA, that has demonstrated the ability to synthesize multiple medications on-demand and as-needed using yeast. The discovery could soon revolutionize our ability to deliver medicine after natural disasters or to remote locations.

Let’s stick with the metaphor of an epi-pen. First, the user presses the actuator, which mixes a chemical trigger into a culture of engineered Pichia pastoris cells. Upon exposure to certain chemical triggers, the cells are programmed to produce a protein: in the report, the team used estrogen β-estradiol, which caused the cells to express recombinant human growth hormone (rHGH), and also methanol, which induced the same culture of yeast to make interferon. By controlling the concentration of the chemical trigger and the population of P. pastoris, the team demonstrated that they could make their device produce a dose of either interferon or rHGH on command. To switch between products, they just pushed another button on the microbioreactor, which flushes out the cell culture with clean, sterile fluid.

“…rapid and switchable production of two biologics from a single yeast strain as specified by the operator.” -Lu, Ram et al

Figure 6(a). The principal component of the microbioreactor is a polycarbonate-PDMS membrane-polycarbonate sandwiched chip with active microfluidic circuits that are equipped for pneumatic routing of reagents, precise peristaltic injection, growth chamber mixing and fluid extraction

Figure 6(a). The principal component of the microbioreactor is a polycarbonate – PDMS membrane – polycarbonate sandwiched chip with active microfluidic circuits that are equipped for pneumatic routing of reagents, precise peristaltic injection, growth chamber mixing and fluid extraction.  Image and caption: Lu, Ram et al

It might not be immediately apparent why there’s an advantage to having to tote around bacteria, rather than just having a cartridge of whatever medication you need to deliver. But consider the case of immune reactions in the field. Snake and spider bites can be fatal without the right treatment. Antivenin is hysterically expensive, though, and it needs special storage conditions to last. This device can maintain the yeast at a temperature it likes, until called to produce the necessary substance fresh on demand.

Vaccines, too, are an application for the new device. Remember Balto? The Iditarod commemorates a heroic journey to bring diphtheria antitoxin to a remote Alaskan village in the depths of a legendary storm. We now have a diphtheria vaccine. Senior engineer Tim Lu explains that the device could be used to produce a vaccine to prevent a disease outbreak in a remote village. Think about what Doctors Without Borders could do if they had a steady supply of vaccines created by a milliliter-scale device like this. “Imagine you were on Mars or in a remote desert, without access to a full formulary, you could program the yeast to produce drugs on demand locally,” Lu said.

MIT DARPA biopharmaceuticals on demand

Point-of-care biomanufacturing employs engineered yeast and portable microbioreactors for on-demand drug production, such as in an ambulance. Credit: MIT

This project builds on prior art, also from MIT. The cells are held within a table-top microbioreactor which contains a microfluidic chip, itself originally developed by Rajeev Ram, a professor of electrical engineering at MIT, and his team, and then commercialized by Kevin Lee — an MIT graduate and co-author — through a spin-off company.

So far, the system has been prototyped. The researchers are now investigating the use of the system in combinatorial treatments, in which multiple therapeutics, such as antibodies, are used together. Combining multiple therapeutics in this way can be expensive if each product requires its own production line, Lu says. “But if you could engineer a single strain, or maybe even a consortia of strains that grow together, to manufacture combinations of biologics or antibodies, that could be a very powerful way of producing these drugs at a reasonable cost.”

(Images courtesy of MIT)

Source: ExtremeTech

Where are all the large impact craters on Ceres?

Where are all the large impact craters on Ceres?

Think of an asteroid. Doesn’t matter which asteroid. Odds are good you thought of something that looks like a lumpy, craterous potato. Astronomers agree with you — most of the rocks in our asteroid belt look pretty careworn. So they expected that when NASA’s Dawn spacecraft got to Ceres, they would see similarly many large impact craters marring the dwarf planet’s surface, just like every other rocky thing in our entire solar system. But that’s not what they found. Ceres is strangely smooth.

Scientists working on the problem have just published some ideas about why this is so. One hypothesis is that Ceres’ own internal structure is responsible. Recent studies, including several detailed analyses of the dwarf planet’s bright spots, points to a layer of ice and salt just beneath the surface. Over geologic time, a process known as “viscous relaxation” could have smudged out the details of the surface. It’s not unlike how the freeze-thaw process breaks down rocks over time. Co-author Michael Bland of the USGS said viscous relaxation flattens out big craters faster than small craters.

The other major hypothesis is cryovolcanism. “We have these bright spots all over the surface – clearly, that’s stuff that came out of the interior,” said Simone Marchi, another co-author. It’s possible that an early period of intense cryovolcanic eruptions dramatically altered the planet’s surface, changing a much different early surface into what we see today. Pearlescent, sparkling cryolavas consisting of phyllosilicated ammonia slush could have obliterated craters, filling them in or abrading them away.

Dawn's trajectory through the solar system, starting when it departed from Earth in 2007. Dawn's orbit around the sun is shown in blue. When the spacecraft is in orbit around Vesta or Ceres, its trajectory is the same color as their heliocentric orbits, which are bold when Dawn is accompanying them around the sun. Dawn is carrying out its extended mission in Ceres' permanent gravitational embrace. Image credit: NASA/JPL-Caltech


Data from Dawn could offer us answers. The spacecraft is currently in a low-altitude orbit, snapping high-res photos that NASA puts online in an enormous, daily updated gallery. “With this high-resolution data, we can look more specifically at sites on the surface that may have evidence of large-scale cryolavas,” Marchi said.

Dawn has high-res imaging capabilities in both the visible and the IR bands. It also has instrumentation collecting data on the gravity field surrounding Ceres, and that will give us a clearer understanding of Ceres’ interior.

Speaking of what the spacecraft can do: Dawn’s original goal was to orbit Ceres and Vesta, two protoplanets in the asteroid belt between Mars and Jupiter. This latest barrage of data marks the successful conclusion of its mission. But, looking at the stalwart little spacecraft’s persistent good health, NASA decided to extend the mission and keep Dawn in orbit around Ceres. The extended mission will continue to extract data from the icy protoplanet, doing science from the asteroid belt until 2019.

Source: ExtremeTech

The Human Connectome Project zeroes in on the firmware of the brain

The Human Connectome Project zeroes in on the firmware of the brain

Is the mind an emergent property of the brain, or is it something… else? Cartesian dualism is a polarizing topic, but like many other ideas that we thought were the province of philosophers, we’re getting light shed on it from a surprising source. Researchers from the Human Connectome Project (HCP) have just released our best-ever functional map of the human brain. It’s twice as finely detailed as anything that has come before it — and it’s tiptoeing closer to settling the mind-body problem. As it turns out, the brain as computer analogy has its shortfalls.

“The brain is not like a computer that can support any operating system and run any software,” says neuroscientist David Van Essen, Principal Investigator of the Human Connectome Project. “Instead, the software — how the brain works — is intimately correlated with the brain’s structure — its hardware, so to speak. If you want to find out what the brain can do, you have to understand how it is organized and wired.”

Image: Glasser, Van Etten et al

Because different subsurface brain structures look more or less the same from the outside, neuroscientists have heretofore relied mostly on gross anatomy and unfortunate happenstance to tell us what parts of the brain did what. (Here’s looking at you, Phineas Gage and Patient H.M.) Structure and function are tightly coupled in the brain, down to the molecular level. But the brain does so many things. Missing borders between brain structures can badly compromise our ability to understand how the brain works.

The HCP has been working for nigh unto six years to shed light on this problem. Their most recent announcement is impressive: The project just doubled the spatial resolution of our best known functional map. In doing so, they also integrate several different ways of explaining differences between brain regions. The researchers report that they’ve found a total of 180 distinct areas per hemisphere, regions which are bounded by sharp changes in cortical architecture, function, connectivity, and/or topography. This development stands to change neuroscience, by opening up our understanding of the relationship between structure and function.

Using multimodal MRI data from the HCP and a semi-automated approach, the new “parcellation” of cortical function checked its predictions by comparing them with brain scans from hundreds of healthy volunteers, so that the model could divide functional regions with exquisite accuracy. The parcellation divides both the left and right cerebral hemispheres into 180 areas based on physical differences like cortical thickness, functional distinctions like which areas respond to language stimuli, and differences in the connections between functional regions. If you think of it using the metaphor of, say, Google Maps, this approach combines political maps with satellite imagery; the most important divisions are invisible from a zoomed-out perspective, but important all the same.

Like cartographers from the Age of Exploration, brain cartographers are creating a tool for others to use in exploration and discovery. Prior work on the connectome gave us a directional diagram of information flow through the brain, and a startling semantic atlas that shows where we process the meanings of certain words and abstract topics. This team of researchers hopes that their work will prove an asset to other researchers as they push back the frontier of ignorance.

“We were able to persuade Nature to put online almost 200 extra pages of detailed information on each of the 180 regions as well as all of the algorithms we used to align the brains and create the map,” Van Essen said. “We think it will serve the scientific community best if they can dive down and get these maps onto their computer screens and explore as they see fit.”

Source: ExtremeTech